Several software programs for ESR spectroscopy were written and updated. Work continued on a program for interfacing an IBM PC-compatible computer, Bruker ER200 ESR spectrometer and an Update Instruments stopped-flow mixer. This software was used successfully in several studies. An EPR pulse spectrometer data acquisition and manipulation system (PULSAR) was written in C++ language using the MicroSoft Foundation Class (MFC) and is a Windows 3.1 application. This approach provides better user control over the acquisition process through a standard graphic-user interface. PULSAR was first used to control an EPR saturation-recovery spectrometer; however, it may be used with simpler measurement units such as a standard Varian console. An MS-Windows version of our data-acquisition program VIKING was begun; however, due to the huge variety of possible spectrometer configurations, it was not possible to configure the system for an arbitrary spectrometer. PULSAR has also been used as the control system for our multiquantum spectrometer.